The function of the endocrine system

Functions

1) To secrete the hormones which are required to regulate many bodily functions
2) To provide chemical systems of communication via the blood stream

Glands are an organ in the body which secrets a particular chemical substance

Hormones are chemical messengers that travel in the bloodstream and they are released by glands

Works alongside the nervous system to control vital functions

Gland, Hormone and Function

Adrenal gland

Adrenaline

Secretes adrenaline and controls the sympathetic division in the fight or flight

The two adrenal glands sit on top of the kidneys, the outer part of each gland is called the adrenal cortex and the inner region is known as the adrenal medulla

The adrenal medulla releases adrenaline and noradrenaline, hormones that prepare the body for fight or flight

Pituitary gland

Oxytocin or ACTH

Controls the release of hormones from other glands casuing them to secrete their hormones or directly produces effects

Is located in the brain and is often called the master gland because it controls the release of hormones from all the other endocrine glands in the body

Releases ACTH as a response to stress

Pineal gland

Melatonin

Receives info from the SCN to release the hormone melatonin which induces sleep

Fight or Flight

When faces with a threat, the amygdala is mobilised. It associates sensory signals with emotions associated with fight or flight e.g anger. It then sends a distress signa; to the hypothalamus which functions like a command centre in the brain communicating with the rest of the body through to SNS

  1. A stressor is identified and the amygdala sends the signal to the hypothalamus which activates the sympathetic brance of the ANS
  1. adrenaline and noradrenaline are released by the adrenal medulla into the blood stream

Role of adrenaline:

  • Increase oxygen to the brain for rapid response
  • Diverts blood away from the skin, kidneys and digestive system to muscles
  • Digestion stops reducing salivation and causes a dry mouth

  1. The fight or flight response is produced preparing the body for sudden physical action e.g increased heart rate, blood pressure, respiration

Fireman SAM

S ympathetic
A drenal
M edulla

A03:

A weakness is there is gender bias as the fight or flight response assumes a universal stress response to a threatening situation should be the same for everyone however evidence suggests females focus their energy on carrying for their offspring and form a defensive network with other females this is known as tent and befriend

Alternative explanation e.g freeze stage this allows for animals and human to be alert and check the situation this is an adaptive response to stress to help look for new info suggesting that fight and flight response is not a full explanation